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I have conduit (plastic at both ends but I can't confirm no metal conduit somewhere in between) running underground to an outlet in my yard that needed to be replaced. I switched off the breaker and cut the wires from the outlet before realizing that there were 3 individual wires running through the conduit, not 3 wires together. All 3 wires are insulated so the ground isn't a bare copper wire. The green wire SHOULD be the ground but it appears that the little piece that remains attached to the neutral on the outlet is green. What would happen if I mixed up the neutral and the ground? The new outlet is a GFCI for outdoor use. At the breaker, the ground is bare copper so the wire must be spliced somewhere or jumped off another outlet. enter image description here

Thank you for your replies. I just added the picture of the original outlet with what appears to have the piece of green wire attached to the white/neutral which is the basis for my concern. Since getting these mixed up creates a safety issue, do you have any suggestions on how to figure out which is which? I have the breaker turned off for the time being for obvious reasons.

  • Is the white wire attached to the ground terminal? – ThreePhaseEel Jul 4 '17 at 4:22
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It will cause a lot of safety problems if you do that, but not immediately. If anything else goes wrong in the circuit, it can have a variety of effects. One example is putting hot voltage on your grounds on that circuit, e.g. Every cover screw, chassis of lamps and machines, etc.

It will immediately trip GFCI/RCDs and some AFCIs, which might cause a frustrated user to remove them and go unprotected.

Green insulated wire is ground wire. Ground doesn't need to be insulated, but if it is, it'll be green or green/yellow. That applies internationally, it's the closest there is to a world standard.

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If you swap the two, then you have normal circuit current flowing on the ground wire and potential ground fault current flowing on the neutral wire.

The latter is not as serious as the former.

Contrary to popular belief, the neutral wire is not "safe" as it has current flowing on it under normal circuit operation. If you pull it apart in an operating circuit, you now have a hot wire in one hand and a grounded conductor in the other.

Imagine now, someone's surprise, when they separate the Equipment Ground wire in your circuit thinking it is an equipment ground and get in the middle of an operating circuit. They could be electrocuted. Not good.

So, to prevent this, the National Electrical Code prohibits the connection of the equipment ground and neutral at any point other than the service. So, normal current only flows on the neutral.

Good luck and stay safe!

  • One exception in the NEC that allows equipment ground and neutral to tie together is in existing dryer circuits. – Kris Jul 6 '17 at 1:02

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